The Effectiveness of Antacids

THE EFFECTIVENESS OF ANTACIDS. Erin. The purpose of the experiment was to measure the effectiveness of antacids and compare different brands. To determine the base content of each antacid, acid base titration was used. Antacids used were Rolaids, Walgreens brand antacid tablets, Walgreens brand antacid liquid, and Tums. The antacids were titrated using 0.1 M hydrochloric acid and phenolpthalein was used as a pH indicator. The amount of acid needed to titrate one serving of Rolaids was 2.1 mL, Walgreens brand antacid tablets 1.1 mL, Walgreens brand liquid antacid 2.3 mL, and Tums 1.6 mL. The calculated amounts of acid needed to neutralize the base in each antacid tablet were 148 mL for Rolaids, 100. mL for Walgreens brand antacid tablets, 146 mL for Walgreens brand antacid liquid, and 100. mL for Tums. There was a high percentage of error in this experiment. The percent error for the Rolaids was 99%, Walgreens tablets 99%, Walgreens liquid 98%, and Tums 98%. Data discrepancies arose from the usage of phenolpthalein as a pH indicator, which changes at a pH higher than seven and the fact that calcium carbonate is only slightly soluble, making it difficult to tell when all of the base has been reacted. The order of antacids from most effective to least effective, in terms of determined effectiveness, is as such: Walgreens liquid, Rolaids, Tums, Walgreens tablet.

Keywords: titration, solubility, ionic compound, double replacement reaction, acid, base.

RESULTS:

TABLE ONE: ROLAIDS
	Trial 1	Trial 2
Mass of one tablet	1.41 g	1.41 g
Mass of part of tablet	0.69 g	0.70 g
Initial buret volume	7.21 mL	8.12 mL
Final buret volume	8.12 mL	9.25mL

TABLE TWO: WALGREENS
	Trial 1	Trial 2
Mass of one tablet	1.28 g	1.28 g
Mass of part of tablet	0.66 g	0.65 g
Initial buret volume	4.89 mL	5.21 mL
Final buret volume	5.21 mL	6.01 mL

TABLE THREE: WALGREENS (Liquid)
	Trial 1	Trial 2
Volume of antacid	4.28 mL	7.95 mL
Initial buret volume	2.10 mL	3.15 mL
Final buret volume	3.15 mL	4.89 mL

TABLE FOUR: TUMS
	Trial 1	Trial 2
Mass of one tablet	1.29 g	1.29 g
Mass of part of tablet	0.64 g	0.63 g
Initial buret volume	6.01 mL	6.65 mL
Final buret volume	6.99 mL	7.21 mL

TABLE FIVE: PERCENT OF TABLET USED
	Trial 1	Trial 2
Rolaids	49%	50%
Walgreens Tablet	52%	51%
Walgreens Liquid	43%	80%
Tums	50%	49%


TABLE SIX: HCl VOLUME
	Trial 1	Trial 2
Rolaids	0.91 mL	1.13 mL
Walgreens Tablet	0.32 mL	0.80 mL
Walgreens Liquid	1.05 mL	1.74 mL
Tums	0.98 mL	0.56 mL


TABLE SEVEN: HCl PER SERVING
	Trial 1	Trial 2	Average
Rolaids	1.9 mL	2.3 mL	2.1 mL
Walgreens Tablet	0.62 mL	1.6 mL	1.1 mL
Walgreens Liquid	2.4 mL	2.2 mL	2.3 mL
Tums	2.0 mL	1.1 mL	1.6 mL


TABLE EIGHT: ACTUAL AMOUNT NEEDED TO TITRATE ONE SERVING
Rolaids	148 mL
Walgreens Tablet	100. mL
Walgreens Liquid	146 mL
Tums	100. mL


TABLE NINE: PERCENT ACCURACY ERROR
Rolaids	99%
Walgreens Tablet	99%
Walgreens Liquid	98%
Tums	98%

2HCl(aq) + CaCO3(aq) → H2CO3(aq) + CaCl2(aq)

2HCl(aq) + Mg(OH)2(aq) → 2H2O(l) + MgCl2(aq)
2HCl(aq) + Al(OH)3(aq) → AlCl3(aq) + 3H2O(l)

LINK TO JOURNAL ARTICLE

Miller AW, Reynolds AC, Sobrino C, Riedel GF. (2009). Shellfish Face Uncertain Future in High CO2 World: Influence of Acidification on Oyster Larvae Calcification and Growth in Estuaries. PLoS ONE 4(5):1-8. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0005661